Originally posted by Tom Kalbfus:
Einstein invented the notion of time-space, where time is the forth dimension. Most particles take up 3 dimensions spacially and the fouth for time, but which dimension is the time dimension? Is there some unique property of the forth dimension that causes it to be used as the time axis for the particles in our domain or is it merely chance that caused it to be that way?
At this juncture of our tech level, I can only offer my opinion. I do think that the time dimension is fundamentally different from the rest. First off, it does not commute with the other three nicely. In some forms of the metric, the time dimension is given an 'i', multiplied by the square root of negative 1, while in most, it is of a reverse sign than the other 3 spatial dimension. Using the same sign gives a garbled or wrong answer to the question the metric was trying to determine.
Einstein was able to combine space and time into a single concept, because the Lorentz contractions worked on BOTH space AND time. And by including time in the dimensional structure, this does make it conceptually easier, as well as fit observation.
But how you can swap time for space, I don't really see a way to do it. Or really what the effects would be. Would it be limited to a single spatial dimension, or would it be inclusive of all three? And more importantly, just what is the mechanism or even the meaning of a spatial dimension becoming a temporal one? Is it still a spatial dimension if a particle sees it as a temporal one?
What is the fate of a tachyon?
From what I read, tachyons are thought to decay in energy, which causes them to speed up. They get faster and faster and fly away.
Something I never got, was why it was improper to talk about a photon's frame of reference. It travells at a set speed, does not accelerate or decelerate. Part of the problem is that for the photon, there is no time. Its two endpoints in its flight path are essentially, in its frame, identical. There is no time elapse for the photon between its origin and its destination, even though millions of years might elapse for us between the two events.
Only the high energy tachyons would still linger, these would be the tacyon equivalent to cosmic rays, they'd go only a little faster than the speed of light.
Not according to standard tachyon theory. Only the low energy or fastest tachyons would survive.
I don't know about black holes, I try to stay away from them for the most part, they do have one useful property though, they can turn a tachyon around 180 degrees since they bend space.
you might want to investigate Kerr Newman black holes. These have a double event horizon, and you can get some really weird effects by slipping between them. But generally speaking staying away from black holes is a good idea. They suck.
Look at the Star Trek Universe as an alternative! ...The whole thing is ugly, and I'd rather have one simply model to cover FTL speeds.
I could not agree more if I tried with all my might. However, a lot of that is unnecessary, and more due to dramatic concerns rather than actual travel concerns.
And again, I want to plug Alcubierre's work. It does take care of the FTL problem, and to date, it is logically consistent with GR and what we know. The "rubber science" needed to incorporate it are minimal
Traveller has this Jump Drive, you press a button and you spend a week in this undefined space called Jump Space. You fuse a substantial fraction of the ships volume in hydrogen to go a specified distance and you have to keep adding power to the jump drive to keep the ship from disappearing in jump space. If you leave the ship while in Jump space or your power plant conks out, you disappear forever! I don't like all this bogus Jump space physics.
I can sympathize with you here. I have many of the same feelings. However, I will point out there are some dramatic concerns that Jump drive does cover, and I think was designed essentially for those concerns.
Earlier in another post, I was sentenced either to a special hell or the rubber room for noting that if your FTL speeds get too high, you get too much cross culture, or cross planet/system contamination of the cultural sort. Things like McDonald franchises scatter throughout the 11,000 worlds become much much easier as you are able to move faster. Before long the entire galaxy begins to look very Vland.
If the entire galaxy becomes copies of a single world, your chances for diverse adventures decrease dramatically. So you need FTL for Traveller (or any science fiction/space opera game) but you have to keep the speeds down, or else you will essentially be only going to the same planet again and again and again.
Also, fuel considerations govern cargo load. Even if you have slow FLT, big ships with lots of goods can cancel out many of the anti-homogenizing effects that slow FTL presents. So you kind of have to restrict it to small ships (relatively speaking) and slow FTL if you want to create a universe that is diverse culturally, and spread out
So might I suggest working on the problem backwards. Identify in game terms what you need to accomplish with your FTL drive, and then work out the physics based on what you know, as well as what is believable to you and your players. What kind of universe you want, will go far in aiding this kind of analysis.
The pilot then has to worry about whether the next stay system is close enough to make it in a single jump and large empty spaces between stars become barriers.
This is a feature, not a bug. making players worry about making it to the next system, or essentially blocking off some systems appears to be a design consideration, rather than a flaw. I can't address the insanity issue too much, as I never got it.
I don't know if its physically possible to go FTL in this manner, but I think gamewise it sure beats the Star Trek Warp Drive or the Traveller Jump Drive, because in those systems everywhere you go you run into bogus physics. FTL is only a mechanism to get from one star system to the next, I don't want it to dominate the story and have to revisit it by adding one patch of bogus physics on top of another to cover different situations. Sometimes in Star Trek you want to have time travel, but most of the time you don't, the rules of FTL travel are consistent.
Well again, because I ain't got my very own personal starship, I can only offer opinion. I will note that Star Trek appears to be the impetus for Alcubierre's work however, that there is less required rubber science today than there was 30 years ago, when either Star Trek and Traveller were first created. And that Alcubierre's paper did help me get to some semblance of competence in dealing with GR and the math especially. As a matter of fact, there is at least one physics professor that uses the paper and the subsequent arguments as a teaching tool for his GR class.
I have noted where your system deivates from what is thought to be known at this time, or what is theoretically conjectured as of now. It is my opinion that there is still too much rubber physics for me. I have strong doubts that tachyons exist, and it boils down to the meaning of imaginary numbers and what it means in the real world. I am not saying that such numbers do not have their place in reality. I have noted an experiment that found Mandlebrot structures in the real world, which indicate that despite their name, imaginary numbers do have some physical reality.
aragraph: The idea of inverting time and space for FTL is a curious one, but ultimately unworkable. For example, the prevailing mathematical solution for GR causes a "convolution" (iirc, that is the technical term) when curvature reaches extremes near a massive singularity. The the radial spacelike dimension and the timelike dimensions get crossed, as it were, such that each dx is also a -dt. This is why photons can't escape, because they curve back on themselves. Otherwise it would make no difference how steep the gravity well, nothing could prevent a photon from eventually escaping.
